1. Field of the Invention
The invention relates to a boost device, more particularly to a DC-to-DC boost device.
2. Description of the Related Art
FIG. 1 illustrates a conventional boost device disclosed in U.S. Pat. No. 7,161,331. The conventional boost device includes a coupling circuit 10, a switch 13, a first diode 121, a second diode 122, an output diode 123, a first capacitor 141, a second capacitor 142, and an output capacitor 143. The coupling circuit 10 includes a first winding 11 and a second winding 12 each having a polarity end and a non-polarity end. The polarity end of the first winding 11 is coupled to an external power source. The first diode 121 has an anode coupled to the non-polarity end of the first winding 11, and a cathode coupled to an anode of the second diode 122. A cathode of the second diode 122 is coupled to the non-polarity end of the second winding 12 and an anode of the output diode 123. The first capacitor 141 is coupled between the cathode of the first diode 121 and ground. The second capacitor 142 is coupled between the non-polarity end of the first winding 11 and the polarity end of the second winding 12. The output capacitor 143 is coupled between a cathode of the output diode 123 and ground. The switch 13 is coupled between the non-polarity end of the first winding 11 and ground, and is operable between an ON-state and an OFF-state. Since the operation of the conventional boost device is described in detail in the aforesaid patent, further discussion of the same is omitted herein for the sake of brevity.
However, such a conventional boost device cannot provide electrical isolation. Thus, for an outdoor power supplying appliance including the conventional boost device, lightning strike may result in damage to the conventional boost device.